The catastrophe of catastrophic antiphospholipid syndrome: a case report.

Background: Catastrophic antiphospholipid syndrome (CAPS) is a rare, life-threatening variant of antiphospholipid syndrome (APS), characterized by rapid-onset thrombosis affecting multiple organs in the presence of antiphospholipid antibodies. Catastrophic antiphospholipid syndrome is often triggered by an underlying condition, such as infection or malignancy. Early diagnosis and initiation of combination therapy are crucial, given the associated high morbidity and mortality. Case summary: A 74-year-old woman presented with progressive dyspnoea and acute right-hand ischaemia. Imaging and laboratory work-up revealed widespread arterial and venous thromboses, including pulmonary embolism, brachial artery embolism, carotid artery involvement, and popliteal vein thrombosis. Laboratory tests showed positive lupus anticoagulant, raising suspicion for CAPS. She was treated with intravenous unfractionated heparin, high-dose corticosteroids, and intravenous immunoglobulins. A PET-CT revealed suspected pulmonary adenocarcinoma, which was confirmed via lymph node biopsy. Following initial clinical improvement and discharge on warfarin, she was readmitted with critical limb ischaemia and later on she suffered an ischaemic stroke. Despite endovascular interventions, her condition deteriorated. Given her poor prognosis and ineligibility for oncologic therapy, comfort care was initiated. The patient passed away a few days later. Discussion: This case highlights the diagnostic and therapeutic challenges of probable CAPS in the context of occult malignancy. Catastrophic antiphospholipid syndrome should be considered in patients presenting with simultaneous arterial and venous thrombotic events. Underlying malignancy may contribute to treatment resistance and worsen prognosis, emphasizing the need for early recognition and multidisciplinary management.